As was observed in the preceding chapters, arguments may yet be advanced in favour of the opinion that species are stable (at least in the intervals of their comparatively sudden successive manifestations); that the organic world consists, according to Mr. Galton's before-mentioned conception, of many facetted spheroids, each of which can repose upon any one facet, but, when too much disturbed, rolls over till it finds repose in stable equilibrium upon another and distinct facet. Something, it is here contended, may be urged, in favour of the existence of such facets—of such intermitting conditions of stable equilibrium.

A view as to the stability of species, in the intervals of change, has been well expressed in an able article, before quoted from, as follows:—“A given animal or plant appears to be contained, as it were, within a sphere of variation: one individual lies near one portion of the surface; another individual, of the same species, near another part of the surface; the average animal at the centre. Any individual may produce descendants varying in any direction, but is more likely to produce descendants varying towards the centre of the sphere, and the variations in that direction will be greater in amount than the variations towards the surface.” This might be taken as the representation of the normal condition of species (i.e. during the periods of repose of the several facets of the spheroids), on that view which, as before said, may yet be defended.